A hydrostatic-mechanical tractor transmission with a variable hydrostatic drive is known from DE 10 2006 025 348 A1. The hydrostatic drive has a hydrostatic pump driven by a combustion engine and a hydraulic motor driven by the pump. The pump and the hydraulic motor are forcibly coupled via a single common pivoting part and can be adjusted such that the pump can be pivoted between a minimum angle and a maximum angle, while the motor synchronously pivots from a maximum pivot angle to a minimum angle at the same time. The pump is designed for only one conveying direction. A mechanical operating range change gear with several shift steps, which can be shifted via a clutch, is connected downstream.
Moreover, DE 19 52 966 A discloses a transmission device with a power distribution that comprises a variator, a double planetary gear set and a manual transmission unit to realize several driving ranges. The pump means and the motor means of the variator, which is configured as a hydrostatic device, can be adjusted via a common yoke.